Drawing and flattening table for sheet glass



'mch 2 1926 1,575,007 C. A. ROWLEY DRAWING AND FLATTENING TABLE FOR SHEET GLASS Filed Jan. 1924 Patented Mar. 2, 1926.

UNITED STATES PATENT OFFICE.

CLIFFORD A. ROWLEY, OF TOLEDO, OHIO, ASSIGNOR TO THE LIBBEY-OWENS SHEET GLASS COMPANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO.

DRAWING AND FLATTENING TABLE FOR SHEET GLASS.

Application filed January 30, 1924. Serial No. 689,398.

T 0 all whom it may concern:

Be it known that I, CLIFFORD A. ROWLEY, a citizen of the United States, residing at Toledo, in the county of Lucas and State of Ohio, have invented new and useful Improvements in Drawing and Flattening Ta-' bles for Sheet Glass, of which thefollowing is a specification.

This invention relates to improvements in the art of drawing sheet glass, and more particularly to an improved apparatus for drawing and flattening the glass sheet.

I In the patent'to Colburn, 1,248,809, granted December 4, 1917, is disclosed a process and apparatus for drawing the sheet of glass upwardly from a, pool of molten glass, bending the sheet while still plastic about a cooled bending roller, and then carrying the sheet horizontally over a traveling draw ing and flattening table and thence into the leer. The present invention relates to a new and improved form of the drawing and flattening apparatus and is especially adapted for use in a sheet drawing system such as just described.

The improved drawing table comprises a plurality of closely positioned parallel rollers, preferably driven, the upper sheet carrying portions of the cylindrical surfaces of the rollers all being tangent to the same horizontal plane. These rollers carry the main central body portion of the sheet, In combination with the rollers, each edge portion of the sheet is gripped between a pair of endless linked belts which draw and support these edge portions of the sheet. Preferably, the two pairs of linked belts diverge from one another in the direction of travel of the sheet so that additional lateral tension is imparted to the sheet as it passes over the lower flattening table. This lateral tension assists in flattening the sheet, and also counteracts the tendency of the still somewhat plastic sheet to sag at the unsupported points between adjacent rollers.

The objects'and advantages of the invention will be more clearly understood from the following detailed description of one approved form of the apparatus.

In the accompanying drawings:

Fig. 1 is a side elevation, partly in section, of portions of the drawing and flattening mechanism.

Fig. 2 is a plan view of the drawing and flattening mechanism, and adjacent portions of the sheet-drawing system, the upper chain loops being omitted.

Fig. 3 is a transverse section on an enlarged scale through one pair of edge-drawing chains and adjacent ends of one of the rollers.

Glass sheet 1 is drawn upwardly from the pool of molten glass 2, and then bent over cooled bending roller 3 into thehorizontal planediate supporting rolls such as 4, sheet lpasses through the drawing and flattening mechanism forming the subject-matter of this invention, and then passes onto the conveying rollers 5 in leer 6.

The main sheet-supporting portion of the drawing and flattening table consists of'a plurality of closely positioned, parallel, cylindrical rollers 7. These rollers may be in the form of long continuous cylinders as shown at 7, or may be in the form of a series of spaced, short, cylindrical discs 8, mounted or formed on a supporting shaft 9. The discs 8 on one shaft move in the spaces 10 between discs 8 on the adjacent shafts. In this way each adjacent pair of shafts 9 may be brought more closely together,-and the length of the unsupported stretch of glass sheet between adjacent rollers is considerably diminished. As shown in the present drawings that portion of the tablenearest the sheet source, where the glass is most plastic, is made of the interlocking discs just described, whereas the opposite end of the table where the sheet has become cooler and more self-supporting, is made of a series of the cylindrical rollers 7. Obviously, the entire table could be made of the interlocking discs, or the entire table could be made of cylindrical rollers 7, and it is to be understood that the present invention covers the use of any of these combinations of rollers. The supporting shafts 9 for the several rollers project through the side walls 11 and 12 of the machine and are rotatably mounted in the continuous bearing blocks 13 and 14 mounted at the outer sides of the machine.

These supporting rollers may be idlers, in which case they should be mounted on rollerbearings. However, the rollers are preferably driven, to assist in drawing the sheet. One end of each shaft 9 is provided with a Worm wheel driven from a worm 15 After passing over certain intermemounted on a driving shaft 16 or 17 The sheets to sag between acqacent supporting similar shafts 16 or 17 at the two sides of the machine are geared together, for exampleby the sprockets l8 and connecting chain 19, so as to turn simultaneously and at the same speed. As here shown, alternate rollers are driven from alternate sides of the machine. This arrangement is mere ly to provide room for the driving gearing for the closely positioned rollers. Obviously, gearing could be arranged to drive all of the rollers from the same side of the apparatus.

Each edge portion of the glass sheet 1 is supported upon a continuous belt conveyor, here shown as a linked chain 20. This chain is in the form of an endless loop traveling over suitable sprockets 21 and 22, and the upper sheet-carrying run of the chain being slidably supported upon the upper horizontal surface of a frame-bar 28. The shafts 9 for the several rollers project through openings 2st in this bar or trackway 23. Preferably, the supporting sprockets 21 and 22 and the supporting trackway for each of the conveyors 20 are positioned in a vertical plane which diverges somewhat in the direction of travel of the sheets, from the center-line of glass sheet 1. In other words, the conveyor chains at the two sides of the sheet separate slightly from one another as they move forward with the sheet. The outermost links of chain 20 are provided with downwardly extending flanges 25 which engage the outer edges of tracks 23 to compel the chains to move along their diverging courses against the resisting action of the glass sheet 1 carried thereby.

A second pair of loop chains 26, which may be of any suitable form having the necessary weight, are carried by sprockets 27 and 28, and the lower loosely hanging run of each chain loop rests its weight upon the edge portion of the sheet 1 above the supporting chain 20. In this way the edge portion of the sheet is gripped between the two chains 20 and 26 which support and hold it flat in the horizontal plane. The two chains 20 and 26 are driven at the same linear speed, which speed is the same as the peripheral speed of the several supporting rolls 7 or 8. The outer links of the upper chain loops 26 have flanges 29 traveling behind fixed cam rails 30. These co operating flanges and cam rails compel chains 26 to follow the same diverging paths as supporting chains 20.

The pairs of chain loops 20 and 26 not only support and draw along the edge portions of the sheet, but also tend'to draw these edges laterally and apply a sidewise stretching tension in the body of the sheet.

This tension assists in flattening the sheet and counteracts the tendency of the moving rollers. When the sheet 1 has become set, and has lost its plasticity to an extent that it is incapable of being stretched laterally, the edges of the sheet will slip or draw inward between the two chains 20 and 26, but

there will be a continual lateral pull on the sheet which tends to hold it flat and prevents sagging.

The main central portion of the sheet is supported during its setting and flattening period upon the rotating rollers 7 or 8. Thus the points of support of the sheet are continually changing, and the somewhat plastic sheet does not have time to settle into holes or depressions in the supporting member and become marred thereby, as is sometimes the case where the entire sheet is supported during the flattening period upon a meshed or linked chain which moves with the sheet.

I claim:

1. In a sheet glass drawing apparatus, a supporting and flattening table for the moving sheet, formed of a plurality of closely positioned parallel rollers, the upper sheetsupporting surfaces of the rollers all lying in the same plane, in combination with continuous means at the sides of the table for supporting and drawing longitudinally the edge portions of the sheet.

2. In a sheet glass drawing apparatus, a supporting and flattening table for the moving sheet, formed of a plurality of closely positioned parallel positively driven rollers, the upper sheet-supporting surfaces of the rollers all lying in the same plane, in combination with continuous means at the sides of the table for supporting. and drawing longitudinally the edge portions of the sheet.

3. Ina sheet glass drawing apparatus, a supporting and flattening table for the moving sheet, formed of a plurality of closely positioned parallel rollers, the upper sheetsupporting surfaces of the rollers all lying in the'same plane, in combination with a pair of link belts at each side of the table for supporting and drawing the edge portions of the sheet.

4.. In a sheet glass drawing apparatus, a supporting and flattening table for the moving sheet, formed of a plurality of closely positioned parallel positively driven rollers, the upper sheet-supporting surfaces of the rollers all lying in the same plane, in combination With a pair of link belts at each side of the table for supporting and drawing the edge portions of the sheet.

5. Ina sheet glass drawing apparatus, means for gripping the edge portions of the sheet, means for moving the gripping means longitudinally with the sheet to draw the sheet from its source, means for simultaneously moving the gripping meanslaterally to tension the sheet laterally, and a plurality of rollers intermediate the two sets of edgegripping devices for supporting the main central portionof the sheet.

6. In a sheet glass drawing apparatus, means for gripping the edge portions of the sheet, means for moving the gripping means longitudinally with the sheet to draw the sheet from its source, means for simultaneously moving the gripping means laterally to tension the sheet laterally, and a plurality of positively driven rollers intermediate the two sets of edge-gripping devices for supporting the main central portion of the sheet.

7. In a sheet glass drawing apparatus, endless draw-members for gripping the opposite faces of the edge portions of the sheet, to support and draw the sheet lengthwise, means for causing the opposite sets of drawmembers to move away from one another to tension the sheet laterally, and a plurality of rollers intermediate the two sets of drawmembers to support the main central portion of the sheet.

-8. In a sheet glass drawing apparatus, endless draw-members for gripping the opposite faces of the edge portions of the sheet, to support and draw the sheet lengthwise, means i'or causing the opposite sets of draw-members to move away from one another to tension the sheet laterally, and a plurality-of positively driven rollers intermediate the two sets of draw-members to support the main central portion of the sheet.

9. In a sheet glass drawing apparatus, four endless chains of gripping devices, each edge of the glass sheet being gripped between, and supported and drawn lengthwise by two of the chains, means to cause the opposite pairs of chains to move away from one another to tension the sheet laterally, and a plurality of rollers intermediate the two sets of draw-members to support the main central portion of the sheet.

10.- In a sheet glass drawing apparatus, four endless chains of gripping devices, each edge of the glass sheet being gripped be tween, and supported and drawn lengthwise by two of the chains, means to cause the opposite pairs of chains to move away from one another to tension the sheet laterally, and a plurality of positively driven rollers intermediate the two sets of draw members to support the main central portion of the sheet;

Signed at Toledo, in the county of Lucas and State of Ohio, this 26th day of J anuary, 1924-.

CLIFFORD A. ROWLEY. 

